Solar System

As New Year's Eve moved from time zone to time zone across planet Earth, the Mars Exploration Rover (MER) team looked to 2012 and wrapping its eighth Earth year of exploring, while up on the Red Planet Opportunity settled into the "saddle" at Greeley Haven preparing for the onslaught of its fifth Martian winter.

Investing in NASA makes us smarter, improves our lives, and increases our capability to overcome technological challenges. Even more important, though, are the intangible benefits of pride, respect from other nations, respect for our place in the universe, and hope for a future in which we can accomplish even greater things.

The twin GRAIL spacecraft are nearly at the end of their three-month cruises to the Moon. Currently being discussed is an extended mission for GRAIL that would begin after the June eclipse and last through most of December 2012.

Just a few of the amazing photos of Comet Lovejoy that have been taken from the southern hemisphere over the last few days. Comet Lovejoy is the first Kreutz sungrazer to have been discovered from the ground in 40 years, and after its surprising survival of its passage close to the Sun, it has been putting on a spectacular show in southern skies.

When I posted about the really cool Cassini SAR images of Enceladus a few weeks ago, I initially wrote that this was the first-ever SAR image of an icy moon other than Titan. Several people (some readers and two members of the Cassini science team!) corrected that statement: Cassini has performed SAR imaging of other icy moons (including Enceladus) before.

A large team of researchers has announced in a Nature article the discovery of not one, but two, Earth-sized planets orbiting a star named Kepler-20. This article separates the observational facts from the quite-likely-to-be-true inferences from the downstream speculations.